1. Field of the Invention
The invention relates to a cast wheel and, in particular, to a cast wheel having at least one reduced-material portion.
More specifically, the invention includes a cast wheel, which comprises a front edge region following on a wheel rim body. The front edge region is connected to an oppositely located rear edge region via a wheel rim base. The rear edge region has at least one reduced-material portion so that the wall thickness of the cast wheel tapers in the region of the reduced-material portion relative to a peripherally adjacent region. The reduced-material portion is at least partially located in the rear edge region that forms a rearwardly arranged circumferential bead.
The invention further relates to a casting mold for producing a cast wheel with a front edge region following a wheel rim body. The front edge region is connected to an oppositely located rear end region via a wheel rim base. The casting mold comprises at least one elevation of material in the rear edge region, so that the wall thickness of the cast wheel tapers in the region of the elevation of material of the casting mold relative to a peripherally adjacent region.
2. Discussion of Background Information
In order to produce cast wheels with as little mass as possible, designers have aimed to create cast wheels with walls as thin as possible in the front and rear edge regions of the cast wheel.
An aluminum cast wheel is known from U.S. Pat. No. 6,318,466, which has reduced-material portions in the front edge region of the cast wheel for purposes of reducing the weight of the cast wheel. These reduced-material portions may peripherally extend the circumferential channel in the circumferential front bead or peripherally distributed recesses.
According to guidelines generally devised in the automobile industry, it is now required for cast wheels to withstand higher impact stresses. As a result, the rear edge region must be made with a wall thickness that is markedly higher than the wheel rim base, which disadvantageously increases the mass of the cast wheel.
It has basically been known from GB 2 249 063 to provide extending channels, which are substantially circumferential, in the rear edge region located opposite the front edge region. By using these closed, channel-like indentations, the risk of air inclusions formed when casting the cast wheel is reduced. However, these channel-shaped indentations disadvantageously weaken the cast wheel in its rear edge region.